dmaengine: pl330: Fix runtime PM support for terminated transfers

PL330 DMA engine driver is leaking a runtime reference after any terminated
DMA transactions. This patch fixes this issue by tracking runtime PM state
of the device and making additional call to pm_runtime_put() in terminate_all
callback if needed.

Fixes: ae43b3289186 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 87fd015..740bbb9 100644 (file)
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -448,6 +448,9 @@ struct dma_pl330_chan {
 
        /* for cyclic capability */
        bool cyclic;
+
+       /* for runtime pm tracking */
+       bool active;
 };
 
 struct pl330_dmac {
@@ -2033,6 +2036,7 @@ static void pl330_tasklet(unsigned long data)
                _stop(pch->thread);
                spin_unlock(&pch->thread->dmac->lock);
                power_down = true;
+               pch->active = false;
        } else {
                /* Make sure the PL330 Channel thread is active */
                spin_lock(&pch->thread->dmac->lock);
@@ -2052,6 +2056,7 @@ static void pl330_tasklet(unsigned long data)
                        desc->status = PREP;
                        list_move_tail(&desc->node, &pch->work_list);
                        if (power_down) {
+                               pch->active = true;
                                spin_lock(&pch->thread->dmac->lock);
                                _start(pch->thread);
                                spin_unlock(&pch->thread->dmac->lock);
@@ -2166,6 +2171,7 @@ static int pl330_terminate_all(struct dma_chan *chan)
        unsigned long flags;
        struct pl330_dmac *pl330 = pch->dmac;
        LIST_HEAD(list);
+       bool power_down = false;
 
        pm_runtime_get_sync(pl330->ddma.dev);
        spin_lock_irqsave(&pch->lock, flags);
@@ -2176,6 +2182,8 @@ static int pl330_terminate_all(struct dma_chan *chan)
        pch->thread->req[0].desc = NULL;
        pch->thread->req[1].desc = NULL;
        pch->thread->req_running = -1;
+       power_down = pch->active;
+       pch->active = false;
 
        /* Mark all desc done */
        list_for_each_entry(desc, &pch->submitted_list, node) {
@@ -2193,6 +2201,8 @@ static int pl330_terminate_all(struct dma_chan *chan)
        list_splice_tail_init(&pch->completed_list, &pl330->desc_pool);
        spin_unlock_irqrestore(&pch->lock, flags);
        pm_runtime_mark_last_busy(pl330->ddma.dev);
+       if (power_down)
+               pm_runtime_put_autosuspend(pl330->ddma.dev);
        pm_runtime_put_autosuspend(pl330->ddma.dev);
 
        return 0;
@@ -2357,6 +2367,7 @@ static void pl330_issue_pending(struct dma_chan *chan)
                 * updated on work_list emptiness status.
                 */
                WARN_ON(list_empty(&pch->submitted_list));
+               pch->active = true;
                pm_runtime_get_sync(pch->dmac->ddma.dev);
        }
        list_splice_tail_init(&pch->submitted_list, &pch->work_list);